Aruba, April 21 2015 - Allan Akamine has looked all around the winding, palm tree-lined cul-de-sacs of his suburban neighborhood in Mililani here on Oahu and, with an equal mix of frustration and bemusement, seen roof after roof bearing solar panels.

Mr. Akamine, 61, a manager for a cable company, has wanted nothing more than to lower his $600 to $700 monthly electric bill with a solar system of his own. But for 18 months or so, the state’s biggest utility barred him and thousands of other customers from getting one, citing concerns that power generated by rooftop systems was overwhelming its ability to handle it.

Only under strict orders from state energy officials did the utility, the Hawaiian Electric Company, recently rush to approve the lengthy backlog of solar applications, including Mr. Akamine’s.

It is the latest chapter in a closely watched battle that has put this state at the forefront of a global upheaval in the power business. Rooftop systems now sit atop roughly 12 percent of Hawaii’s homes, according to the federal Energy Information Administration, by far the highest proportion in the nation.

“Hawaii is a postcard from the future,” said Adam Browning, executive director of Vote Solar, a policy and advocacy group based in California.

Other states and countries, including California, Arizona, Japan and Germany, are struggling to adapt to the growing popularity of making electricity at home, which puts new pressures on old infrastructure like circuits and power lines and cuts into electric company revenue.

As a result, many utilities are trying desperately to stem the rise of solar, either by reducing incentives, adding steep fees or effectively pushing home solar companies out of the market. In response, those solar companies are fighting back through regulators, lawmakers and the courts.